Dorien Bangma

FDM IN ADULTS WITH ADHD | 165 Procedure and ethics statement The Ethical Committee of the Medical Faculty of the University of Duisburg-Essen, Germany, approved this study. Participants were assessed individually. The total duration of the assessment was approximately 4.5 hours. Participants received as many breaks as needed and were given the opportunity to complete the second half of the assessment (i.e., the CFADHD) later in time. Prior to assessment, all participants were informed about the content and aim of the study and signed a written informed consent. Participation was voluntary and participants did not receive any compensation for participation. Data analysis Effect sizes were calculated for all group comparisons and converted to Cohen’s d . Furthermore, 99% confidence intervals (99% CI) were calculated for effect sizes and results were considered significant when p ≤ .010 to control for overoptimism or Type I errors. Effect sizes were interpreted (Cohen, 1988) as small: d = .20 (1- b = .09), medium: d = .50 (1- b = .53) and large: d = .80 (1- b = .94). Cognitive performance . All cognitive variables were normally distributed. Group differences between adults with ADHD and healthy controls on measures of cognition (i.e., CFADHD and WAIS-IV Arithmetic) were determined by using t-tests. One healthy participant and eighteen adults with ADHD did not complete the second half of the assessment (i.e., the CFADHD) due to personal or logistic reasons, resulting in 27 adults with ADHD and 50 healthy controls for these analyses, who did not differ with regard to age ( p = .967), gender ( p = .881), years of education ( p = .781) and work status ( p = .695). The adults with ADHD (n = 27) and healthy controls (n = 50) in the remaining sample did significantly differ on the ADHD measures (i.e., WURK-S p < .001 and ADHS-SR p < .001). Furthermore, no differences were found regarding clinical and demographic variables between adults with ADHD who did and who did not complete the second half of the assessment (i.e., age p = .033, gender p = .324, years of education p = .834, work status p = .962, WURK-S p = .751 and ADHS-SR p = .741). Personal financial situation. Group differences between adults with ADHD (n = 45) and healthy controls (n = 51) with regard to the personal financial situation of participants were evaluated using Pearson’s chi-square tests. Differences in the range of income between groups were analyzed with a Mann-Whitney-U test and group differences on questions about ‘Free money to spend’ and ‘Amount of social security’ were analyzed with t-tests. The variable ‘Free money to spend’ was not normally distributed which was corrected by using a log transformation. FDM performance. To compare the performances of adults with ADHD and healthy controls on FDM tests (n = 45 and 51, respectively), t-tests were performed for each FDM test. All data was normally distributed except for the TDT. Therefore, an arcsine transformation for percentage data (i.e., 2 ∗ #$%&'()*+ ! /100 ; Cohen et al., 2003) was executed which resulted in a normally distributed variable. FDM – clinical interpretation. Based on procedures used in previous studies on FDM (Giannouli & Tsolaki, 2014; Marson et al., 2000; Martin, Griffith, et al., 2008) and in the field of clinical neuropsychology in general, the individual performances of adults with ADHD on